Swap touch selection handles when they are interchanged

ui/touch_selection/touch_selection_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/touch_selection/touch_selection_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 
@@ skipping 71 matching lines @@
 
   // Notify if selection bounds have just been established or dissolved.
   if (start.type() != SelectionBound::EMPTY &&
       start_.type() == SelectionBound::EMPTY) {
     client_->OnSelectionEvent(SELECTION_ESTABLISHED);
   } else if (start.type() == SelectionBound::EMPTY &&
              start_.type() != SelectionBound::EMPTY) {
     client_->OnSelectionEvent(SELECTION_DISSOLVED);
   }
 
+  // Swap the Handles when the start and end selection points cross each other.
+  if (active_status_ == SELECTION_ACTIVE) {
+    if ((start_selection_handle_->IsActive() &&
+         end_.edge_bottom() == start.edge_bottom()) ||
+        (end_selection_handle_->IsActive() &&
+         end.edge_bottom() == start_.edge_bottom())) {
+      start_selection_handle_.swap(end_selection_handle_);
+    }
+  }
+
   start_ = start;
   end_ = end;
   start_orientation_ = ToTouchHandleOrientation(start_.type());
   end_orientation_ = ToTouchHandleOrientation(end_.type());
   force_next_update_ = false;
 
   if (!activate_selection_automatically_ &&
       !activate_insertion_automatically_) {
     DCHECK_EQ(INACTIVE, active_status_);
     DCHECK_EQ(INPUT_EVENT_TYPE_NONE, response_pending_input_event_);
@@ skipping 540 matching lines @@
   return !temporarily_hidden_ && !longpress_drag_selector_.IsActive();
 }
 
 bool TouchSelectionController::GetEndVisible() const {
   if (!end_.visible())
     return false;
 
   return !temporarily_hidden_ && !longpress_drag_selector_.IsActive();
 }
 
+TouchHandleOrientation TouchSelectionController::GetStartHandleOrientation()
+    const {

[mohsen, 2015/11/19 21:35:36]

Can you add this logic directly in |TouchSelectionControllerTestApi| and get rid
of these functions here?

[AviD, 2015/12/11 11:25:53]

Done.

+  if (active_status_ != SELECTION_ACTIVE)
+    return TouchHandleOrientation::UNDEFINED;
+  return start_selection_handle_->orientation();
+}
+
+TouchHandleOrientation TouchSelectionController::GetEndHandleOrientation()
+    const {
+  if (active_status_ != SELECTION_ACTIVE)
+    return TouchHandleOrientation::UNDEFINED;
+  return end_selection_handle_->orientation();
+}
+
 TouchHandle::AnimationStyle TouchSelectionController::GetAnimationStyle(
     bool was_active) const {
   return was_active && client_->SupportsAnimation()
              ? TouchHandle::ANIMATION_SMOOTH
              : TouchHandle::ANIMATION_NONE;
 }
 
 void TouchSelectionController::LogSelectionEnd() {
   // TODO(mfomitchev): Once we are able to tell the difference between
   // 'successful' and 'unsuccessful' selections - log
   // Event.TouchSelection.Duration instead and get rid of
   // Event.TouchSelectionD.WasDraggeduration.
   if (selection_handle_dragged_) {
     base::TimeDelta duration = base::TimeTicks::Now() - selection_start_time_;
     UMA_HISTOGRAM_CUSTOM_TIMES("Event.TouchSelection.WasDraggedDuration",
                                duration,
                                base::TimeDelta::FromMilliseconds(500),
                                base::TimeDelta::FromSeconds(60),
                                60);
   }
 }
 
 }  // namespace ui